(US5130114-A)      Steam reforming hydrocarbons comprises reacting hydrocarbons with steam in the presence of a catalyst comprising (A) at least 1 of Rh and Ru to impart reforming activity and (B) at least 1 of Ni, La, Pr, Nd, Sm, Th, U, Cr, Mg, Ca and Y to impart co-catalyst function. (A) and (B) are supported on the zirconia carrier.    Pref., the amt. of Rh and/or Ru used is 0.1-5 wt.% based on the carrier wt.    ADVANTAGE -   Catalyst has high catalytic activity.    (JP94004135-B2)      Catalysts for the steam reforming of hydrocarbons comprises (I) a zirconia carrier and ruthenium supported thereon; (II) a partially stabilised zirconia carrier, and rhodium and/or ruthenium supported thereon; and (III) a zirconia carrier, and supported thereon rhodium and/or ruthenium to impart reforming activity, and nickel, lanthanum, praseodymium, neodymium, etc. Pref. (I) contains 0.01-5 wt. % ruthenium. In (II) the zirconium is stabilised by an oxide of yttrium, magnesium or cerium; Ru or Rh is 0.1-5 wt. %. In (III) Ru or Rh is 0.1-5 wt. % and the cocatalyst metal is 0.1-10 wt. %. Known methods of prepn. may be used.    USE/ADVANTAGE -   The catalysts have higher activity, heat resistance and mechanical strength and longer life than prior catalysts; they may be used e.g. in a hydrogen-producing plant for fuel cells, and in a small size hydrogen-producing plant.    (JP95090169-B2)      Catalysts for the steam reforming of hydrocarbons comprises (I) a zirconia carrier and ruthenium supported thereon; (II) a partially stabilised zirconia carrier, and rhodium and/or ruthenium supported thereon; and (III) a zirconia carrier, and supported thereon rhodium and/or ruthenium to impart reforming activity, and nickel, lanthanum, praseodymium, neodymium, etc. Pref. (I) contains 0.01-5 wt. % ruthenium. In (II) the zirconium is stabilised by an oxide of yttrium, magnesium or cerium; Ru or Rh is 0.1-5 wt. %. In (III) Ru or Rh is 0.1-5 wt. % and the cocatalyst metal is 0.1-10 wt. %. Known methods of prepn. may be used.    USE/ADVANTAGE -   The catalysts have higher activity, heat resistance and mechanical strength and longer life than prior catalysts; they may be used e.g. in a hydrogen-producing plant for fuel cells, and in a small size hydrogen-producing plant.